A conventional metal-oxide-semiconductor (MOS) transistor generally includes a semiconductor substrate, such as silicon, having a source, a drain, and a conductive gate. The conductive gate is typically located above a gate dielectric layer that is formed on the semiconductor substrate. The mobility of carriers in a channel region in the semiconductor substrate underneath the conductive gate determines the quality of MOS devices.
Generally, for a given electric field across the channel of an MOS device, the amount of current that flows through the channel is directly proportional to a mobility of carriers in the channel. Thus the higher the mobility of the carriers in the channel, the more current can flow and the faster a circuit can perform when using high mobility MOS transistors.
As the demand for faster devices continually grows in the industry, the desire for a device having an increased mobility also increases. Thus, a method for fabricating a device having an increased carrier mobility would be desirable.